1. Field of the Invention
The present invention relates to a crank device, and more particularly to a crank device including a weight reducing structure for reducing the weight of the crank device without decreasing the strength of the crank device.
2. Description of the Prior Art
Typical crank devices comprise one end for securing to a crank shaft and/or a chain wheel of a gear shifting device, and another end for coupling a foot pedal.
For example, U.S. Pat. No. 5,062,318 to Yamazaki discloses one of the typical crank devices that is normally made of molding or mold injection processes, or by die casting processes, or the like, and that also includes one end for securing to a crank shaft and/or a chain wheel of a gear shifting device, and another end for coupling a foot pedal.
However, the molded or die cast typical crank devices include a solid or integral structure made of heavy metal materials and having a great weight, and having no weight reducing structure formed or provided therein such that the weight of the crank device is great or heavy.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional structures of the crank devices.